Known endoscope systems of the related art emit excitation light, which generates agent fluorescence by exciting a fluorochrome accumulated specifically in a lesion, such as cancer cells, to an examination site, which is given the fluorochrome. The endoscope system photographs the generated agent fluorescence so as to acquire a fluorescence image having high luminance in the lesion (for example, see Patent Document 1).    Patent Document 1: Japanese Unexamined Patent Application, Publication No. Hei 8-224208